1. Field of Invention
The present invention belongs to the technical field of a waterproof electric motor structure constituting electrical equipment mounted on a vehicle.
2. Description of Related Art
In general, some of these types of electric motors must be subjected to a high degree of waterproof processing depending upon the locations where they are disposed. In waterproofing such electric motors, portions where a yoke communicates with the inside and outside of the electric motor must be sealed. This can include a portion where the yoke, in which an armature shaft as the output shaft of the electric motor is rotatably accommodated, is coupled with an end bracket for covering the opening end of the yoke. Further, a portion through which a cable is drawn from the outside to supply electric power to brushes and the like must be sealed.
An example of such an electric motor is shown in FIG. 10. A cover member 21 composed of a bottomed cylindrical rubber for covering the opening of a yoke 20 is outwardly engaged with an outer peripheral surface of the yoke and the cover member 21 is sealed by tightening the edge thereof using a hinge tie 22. In this arrangement, since a lead wire 23 for supplying electric power to brushes must be drawn from the outside, a through hole is defined to the yoke 20 and the lead wire 23 is passed therethrough. For this purpose, a cover member through hole must also be defined for the cover member 21 in confrontation with the above through hole.
In this arrangement, the cover member 21 must be manually mounted to the yoke 20 while causing it to be elastically deformed. Further, this must be carried out while aligning the cover member through hole with the yoke through hole. Thus, there is a problem that workability is made inevitably bad and it is necessary to fix the hinge tie 22 to tighten the edge of the cover member 21 for the seal of it. Since all of these steps are carried out manually, dispersion in products is caused.
Furthermore, there is also a problem that both the through holes must be sealed separately and a step of passing the lead wire through the respective through holes is time-consuming and troublesome. Thus, this problem is also a subject to be solved by the present invention.